CYP-dependent induction of glutathione S-transferase in Daphnia similis exposed to a disperse azo dye

Abstract

Disperse Red 1 (DR1) is an azo dye that can reach the aquatic environment through the discharge of textile industrial wastewaters. It has been tested in Daphnia similis and shown to be highly toxic. Cytochrome P450 (CYP) is a class of enzymes involved in phase I of detoxification, while glutathione S-transferase (GST) are a class of phase II enzymes. No information about phase I or II dye metabolism in microcrustacea were found in the literature. In this study we identified CYP and GST enzymes involved in the metabolism of DR1 in juveniles of D. similis. Using spectrophotometric analysis we showed that 50 % of the dye was absorbed by the organisms, which could be confirmed by the reddish color of animals exposed to DR1, however adsorption cannot be ruled out. GST activity increased from 280 to 615 nmol(-1 )min(-1 )mg when D. similis were exposed for 48 h to 0.2 mg L(-1) DR1 and from 274 to 815 nmol(-1) min(-1 )mg when exposed to 5 mg L(-1). Data clearly demonstrate that exposure to DR1 can stimulate a strong induction of GST activity, whose participation in DR1 metabolism needs to be confirmed. The induction of GST activity seems to be dependent on CYP activity, since treatment with SKF535A, a CYP inhibitor, blocked the DR1-dependent GST induction. We speculate that GST is involved in DR1 metabolism in Daphnia and that CYP activity is necessary to induce GST-activity, which is an indirect evidence of its role in the biotransformation of DR1.

Effects of Perfluorooctane sulfonate on immobilization, heartbeat, reproductive and biochemical performance of Daphnia magna

“…GST and CAT were assessed to reflect the response of antioxidant enzymes to PFOS (G omez-Oliv an et al, 2014;Yu et al, 2014). While exposed to toxicants, the body produces oxidative stress and the balance of active oxygen is broken.…”

Generational sensitivity alteration in Chironomus yoshimatsui to carbamate and pharmaceutical chemicals and the effect on Catalase, CYP450, and hemoglobin gene transcription

“…CYP450 is one of the major phase I-type classes of biotransformation enzymes and converts xenobiotic compounds into water-soluble substances (Bonnafé et al, 2015). The relationship between the CYP450 enzyme and toxicity of xenobiotic chemicals to several insects has been studied previously and it has been found that the CYP450 genes were related to insecticide resistance (Dulbecco et al, 2018;Kaplanoglu et al, 2017;Nair et al, 2013;Tang et al, 2017;Yu et al, 2015). The members of the CYP4 family are frequently related to specialized biochemical pathways such as the biosynthesis of endogenous compounds and metabolism of pheromones (Xiong et al, 2019).…”

A simple electrochemical method to monitor an azo dye reaction with a liver protein

“…Azo dyes also interact with enzymes in the liver, e.g. glutathione-stransferase (GST) and cytochrome P450 (CYP) involved in the conversion of xenobiotic compounds to facilitate their elimination [8]. Exposure to such toxic compounds as azo dyes may hamper the GST catalysis of the conjugation of glutathione (GSH) to a wide variety of endogenous and exogenous electrophilic compounds [9], thus leading to cell proliferation in the early stages of oncogenesis [10][11][12].…”